Enabling/Disabling Automatic Logon

1. Click Start on the Windows taskbar, and then click Run.

2. In the Open box, type:

   control userpasswords2 

   then click OK.

3. In the dialog box that appears,
You'll see: "Users must enter a user name and password to use this computer" check box.
Enabled will require users to logon, disabling will make Windows automatically logon to the Administrator account.